This is the fifth part in a series of how to conquer SAT and ACT Math by utilizing a Math Toolbox. For the complete list of the tools in the Math Toolbox and Part 1, visit here.
Now that your toolbox is filling up with tools to conquer SAT and ACT math like your pencil, calculator, mental math and the translator, one of the remaining tools may be the most valuable: the back door.
The back door, or back-solving, means you start with the answer choices at the outset of the problem. Instead of solving an equation to find an answer, plug the answer choices into the equation to find which one solves it.
Think of it this way: for all multiple choice questions, the test writers give you the correct answer. Yes, there are three or four other answers also presented, but the correct answer is staring at you in the face.
So take advantage of that information! Use the back door: insert one of the answer choices into the problem and find your solution through back-solving.
One major key with the back door tool: start with the answer choice in the middle. Answer choices are typically ordered from least to greatest or greatest to least, so start with one of the numbers in the middle. That way, if you find you need a number that is larger, you can eliminate all answers that don’t work without having to solve the problem four or five times.
The back door can also be used to help set up your problem. For instance, on a word problem, a quick peek at the answers can help you frame your equation.
The back door is a simple yet supremely effective way to get to the right answer. Since the answers are given to you, start with the answers and work backwards to find which one is best. While this tool will not help you with the grid-ins on the SAT, it will help on all multiple choice problems in the ACT and SAT.
For more tools and resources on conquering the SAT, ACT, PSAT, SSAT and more, contact CROSSWALK today.